arch/kmap: remove BUG_ON()

Patch series "Remove duplicated kmap code", v3.

The kmap infrastructure has been copied almost verbatim to every
architecture.  This series consolidates obvious duplicated code by
defining core functions which call into the architectures only when
needed.

Some of the k[un]map_atomic() implementations have some similarities but
the similarities were not sufficient to warrant further changes.

In addition we remove a duplicate implementation of kmap() in DRM.

This patch (of 15):

Replace the use of BUG_ON(in_interrupt()) in the kmap() and kunmap() in
favor of might_sleep().

Besides the benefits of might_sleep(), this normalizes the implementations
such that they can be made generic in subsequent patches.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Link: http://lkml.kernel.org/r/20200507150004.1423069-1-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20200507150004.1423069-2-ira.weiny@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arc/include/asm/highmem.h

@@ -45,7 +45,7 @@ static inline void flush_cache_kmaps(void)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/arc/mm/highmem.c

@@ -51,7 +51,7 @@ static pte_t * fixmap_page_table;
 
 void *kmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 

arch/arm/mm/highmem.c

@@ -42,7 +42,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/csky/mm/highmem.c

@@ -29,7 +29,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/microblaze/include/asm/highmem.h

@@ -66,7 +66,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/mips/mm/highmem.c

@@ -28,7 +28,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/nds32/mm/highmem.c

@@ -24,7 +24,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/powerpc/include/asm/highmem.h

@@ -74,7 +74,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/sparc/include/asm/highmem.h

@@ -55,7 +55,7 @@ void kunmap_high(struct page *page);
 
 static inline void *kmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 	return kmap_high(page);
@@ -63,7 +63,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/x86/mm/highmem_32.c

@@ -15,8 +15,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	if (in_interrupt())
-		BUG();
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);

arch/xtensa/include/asm/highmem.h

@@ -73,7 +73,7 @@ static inline void *kmap(struct page *page)
 	 */
 	BUILD_BUG_ON(PKMAP_BASE <
 		     TLBTEMP_BASE_1 + TLBTEMP_SIZE);
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 	return kmap_high(page);
@@ -81,7 +81,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);